1. Field of the Invention
The present invention relates to knives and, more particularly, to knives having replaceable cutting blades or cutting elements.
2. Description of the Prior Art
Knives and other cutting devices such as utility blade holders and the like having replaceable blades or cutting elements are well known in the prior art and various means of blade mounting, retention and disassembly have been proposed. The advantage of this type of knife or cutting device is the ability to rapidly replace the cutting edge either in the field, such as with a hunting or skinning knife, or during use on a job site. The dulled or damaged blades or cutting elements are usually disposable. This approach allows the user to maintain a superior cutting edge in the absence of sharpening implements or sharpening skills which may otherwise be required. The key to the success of such devices lies not only in the ease of blade replacement but also in the means whereby the replaceable blade is rigidly supported and locked to the cutting edge mounting portion of the cutting device.
Following are examples of cutting devices of the foldable or retractable blade type utilizing replaceable cutting elements.
Still other replaceable cutting element structures have been proposed in the prior art for use with fixed-blade knives. The following listed patents are illustrative of this type of structure.
The following listed patents are cited as being of general interest for their showing of knives or cutting implements intended for field dressing and skinning animals utilizing a gut hook.
My prior U.S. Pat. No. 5,689,889 listed above discloses a novel structure wherein a blade replacement insert is disposed between spaced flanking side support members and is engaged with a blade insert locator means in position between the side support members forwardly of the knife handle. This allows the replacement blade to be inserted downwardly through a slot or opening provided by the spaced flanking side support members and moved into position to be retained by the blade insert locator means. The blade locator means, whether a single or multiple part element, includes a locating and locking edge contacted by the blade insert and about which the blade insert is pivoted or fulcrumed during insertion and a seating edge against which the blade insert comes to rest. With these two functions of the locator, the forward end of the blade insert is restrained against upwardly, downwardly, and forwardly directed forces which occur during use. Since the blade locator is contained in the forward portion of the blade component and is structurally separate from the blade insert lock, the locator is not limited to use with fixed blade knives and is equally applicable to foldable blade knives. The replaceable blade insert is locked against removal from between the side support elements by locking means cooperating with and contained within the handle structure. The blade, comprising the side support members, the replaceable blade insert and the blade insert lock thus becomes integrated with the handle in this fixed blade version, both in terms of blade insert replacement structure and function.
According to the present invention, a knife structure is provided which includes the usual blade and handle components, of either the fixed or foldable blade type, with the blade component having a replaceable cutting element or blade insert. In its broadest scope, the present invention contemplates the location of the replaceable blade insert as well as the blade locator means and blade insert locking means totally within the confines of the blade component, separate in both structure and function from the handle component and is not limited to any specific blade locator or blade insert locking means.
The blade component includes elongated side support members which extend forwardly from the handle component and flank the cutting element, the elongated replaceable cutting element being installed and removed by insertion and retraction from between the flanking side supports from the top side of the blade component. The side support members are laterally spaced and are joined together at a position forward of the handle by a blade insert locator means, thus providing a slot between the flanking side members for insertion of the replaceable blade. The blade insert locator means may be either a single or multiple part structure and the term will be expressly understood to refer to such in the present description and claims. The insert locator means provides a locating and locking edge or point initially contacted by the blade insert and about which the blade insert is fulcrumed during insertion and a seating edge or surface against which the blade insert comes to rest. These two structural features of the locator serve to lock the forward end of the blade insert against upwardly, downwardly and forwardly directed forces once it is assembled and locked into position for use.
The inner ends of the side support members are joined by a suitable spacer element providing a pivotal connection to a standard folding knife handle. In the alternative, the side support member and spacer may be extended to form a conventional tang section to the rear of the blade component which extends into the handle portion and may be fixed relative thereto in any manner well understood in the art. Whether the blade component is adapted for a fixed or a folding knife structure, the blade insert is locked into final position between the two side support members by a blade insert locking structure contained wholly within the blade component, independently operable and structurally separate from the handle itself. With this arrangement, the blade component of a folding knife may remain in the locked open position thus allowing the blade insert to be replaced in a safe manner without the risk of closing against the user""s fingers. This feature also provides for a more simplified blade and handle construction when utilized in either the fixed or foldable blade knife arrangement. The foldable blade knife may, of course, be of the lockable or un-lockable type. The fact that the blade insert locking mechanism does not depend upon or interfere with the handle structure accommodates the blade for use with any standard blade lock such as, but not limited to, spring-latch locks, linear locks or button locks. Additionally, since the blade insert lock is located along the upper edge of the side support members forward of the handle component, it does not interfere with movement of the blade relative to the handle in a folding knife structure. The blade insert lock may take any one of a number of configurations, the illustrated and described locking mechanism being a clamping bolt or pin arrangement which connects the inner end of the blade insert to the two side support members. In the alternative, such devices as slide locks, pivotal locks and locking pins of various configurations may also be used.
The blade insert is also provided in various configurations such as, but not limited to, an extended and pointed terminal end, or a blunt, flat or rounded terminal end, designed for various specialized uses. In one embodiment the blade insert incorporates a gut hook, either supported or unsupported by the side support members.